The 3rd Generation Partnership Project (3GPP) is developing the architecture and protocols for the next generation wireless communication networks (e.g., new radio (NR)). An NR network strives to deliver sub-millisecond latency and at least 1 Gbps (e.g., 10 Gbps) downlink speed, and support millions or even billions of connections. In comparison, a 4th Generation (4G) wireless network, such as a legacy long-term-evolution (LTE) network, can support at most 150 Mbps downlink speed with a single carrier. Thus, an NR network may have a system capacity that is 1000 times of the capacity of the current 4G wireless network. The NR exploits, among other things, higher frequencies of the radio spectrum in the millimeter wave range (e.g., 1 to 300 GHz), and dense small cell deployment (e.g., using pico-cells, baseband units, remote radio heads, and other techniques) to meet these technical requirements.
A cloud radio access network (C-RAN) can provide centralized baseband processing of a number of small cells. The C-RAN's abilities to coordinate among these small cells and pooling resources provide flexibility and efficiency to the wireless network architecture. For example, C-RANs may offer many benefits, such as (1) suitability for network function virtualization (NFV); (2) cost (e.g., CapEx, OpEx) reduction; (3) utilization and virtualization of radio resources to provide high system capacity and peak user equipment (UE) throughput; and (4) flexible adaption for different applications and requirements.
C-RANs also promise to support efficient transmission coordination and network function virtualization for the next generation of wireless communication networks. Under a C-RAN architecture, a baseband unit (BBU) can optimize the radio resource management (RRM) for connected remote radio heads (RRH), to satisfy various UE requirements (e.g., high throughput). In addition, massive multi-input-multi-output (M-MIMO) technology with millimeter wave (mmWave) frequency bands is also utilized to achieve high data rate.
However, a traditional C-RAN typically relies on one or more macro evolved node Bs (eNBs) or generation node Bs (gNBs) to cooperate with one or more RRHs for providing control plane (CP) signaling and user plane (UP) content (e.g., data) in order to achieve high throughput transmission in its coverage area. Such cooperation results in increased network overhead, and requires complex configurations on the UE end. As such, a traditional C-RAN may not be suitable and/or desirable for applications such as low cost internet of thing (IoT) devices, vendor factory enterprises, and hospital usage.
Thus, there is a need in the art for a customized C-RAN that can provide CP signaling and UP content without the deployment of network operators (e.g., macro eNBs), and provide a consistent access mechanism for standalone and non-standalone operations of RRHs.